The message to the
future Android developer So, signs are quite positive that you want to have
in-depth knowledge of Java to develop those magnificent Android apps. Good, you
are at the right place. Java has been the basis of Android development since ages
and it is still crucial even after Kotlin. In this post, we explain all you
should know in learning Java for Android development.
Understanding Java
Basics
Well, first of things go first so let us start with
the basics. That the language makes use of a number of Java basics means that
for any Android developer they are the equivalent of their ABCs. These are the
basic things but will help you to fulfill more complex concepts in future. They
are like the bare bones of a house – everything crumbles without them.
Java Syntax and
Structure
So starting learning Java, first learn the syntax
and structure of java programming. This includes:
- Variables and data types: You will need to store information, in order for you to retrieve them later on.
- Operators: These are used to execute operations
involving variables and values. - Control Statements: You best buddies for the
implementation of Logic is if and switch case along with loops.
Another section on
Object-Oriented Programming (OOP) Concepts
Java is Object-Oriented Language so you should know
OOP concepts. Here are the biggies:
- Classes and Objects: Consider classes to be the
blueprint, while objects are product built out of those blueprints. - Inheritance: This enables one class to inherit fields
and methods from another class, thus enabling code reusability. - Polymorphism: This allows programming using the same
interface to access difference type of objects. - Encapsulation: This is a concept in OOP, where you
hide your data and provide access to the components that need it. - Abstraction: Helps you to send only couple of model
classes which is appropriate for pattern from object getModel.
Java Collections
Framework
Up next, The Java Collections Framework. This is one
of the more important feature to utilize if you want to work with object
collections. Key components include:
- List, Set and Map: List are sets/interfaces for a
type of list. - Iterators: Iterating over collections.
- Generics: Type-safe collections.
Exception Handling
in Java
Handling Exceptions – This is a biggie. In the real
world stuff breaks and you need a way to catch errors gracefully.
- Try-Catch Blocks: Used to catch exceptions and
handle them the way you want. - Throw and Throws: We write throw with function where
we can handle exceptions. - Custom Exceptions: You must also create custom exceptions when dealing
with specific scenarios.
File I/O in Java
Another important part is file I/O. Many times
you’ll have to read/write files in your android application.
- File I/O: Java really does provide an incredibly
easy way to deal with file operations. - Android File Handling: Since Android has its own API
for handling files, it is important to understand both of them.
Java Threads and Concurrency
Threads and Concurrency With multicore
CPUs prevalent today, this is very important to understand.
- Threads Tutorials: Threads, The ability of take your
program to do multitask. Basics of threads - Synchronization: To avoid data corruption during the
threads access of shared resource is key concept. - Android Multithreading: For handling multithreading,
Android provides specific frameworks such as AsyncTask and Handler.
Java Networking
Any app that communicates over the internet is going
to need some kind of instantiation for networking.
- Java Network Programming Sockets: How you end up
creating network connections. - Sockets and https URL Connections: These are core
classes provided for network communication in Java.
Java for Android:
An Overview
Well from where Java now fits into the world of
Android development? In short, Android applications are generally wr. quitten
in Java (though Kotlin is widely gaining attention). Here’s a quick comparison:
- Android SDK: Android’s primary language is Java so
native apps are written in java. - Java and Kotlin: Kotlin is more modern and concise Android
Development Language but having Java will give you a firm foundation.
Java Libraries for Android
Several Java Librairies to Ease your Life as an
Android developer
- Most used libs: Retrofit, Glide and Gson are
invaluable. - How They Assist in Development: These libraries
provide a way to complete many common tasks (ex – networking, image loading,
and JSON parsing) as simplified.
Setting Up Your Environment
First, Let me show you how to prepare the
development environment before actually writing any code.
- Installation Java Development Kit (JDK):
This is the first step. - Android Studio Installation (IDE for Android
development)
Your First Android App with Java
Now, the interesting stuff – building an app!
- Starting a New Project: This is one the easiest
things that has done in Android Studio. - An Overview of the Folder StructureFind out Use
Cases: What is it that Redux aims to solve? - Your First Java Code for Android: Finally, now that
the introduction is done… and it’s time to get our hands dirty. Let’s write
some code!
Debugging and Testing Android Java Code
Debugging & Testing : Debugging and testing are
key steps in development process.
- Debugging: How to use Breakpoints and Logs in Common
- Here are the tools I use for testing: For unit test
cases – JUnit- For Android Instrumentation Test – Espresso
FAQs
1. How Much Java Should I Learn for Android Development?
Ans: You should have strong understanding of java basics, OOPs concepts and android
related java skills as well.
2. For Android development, is it possible to use
Kotlin in stead of Java?
Ans: Absolutely, Kotlin is one of the most widely supported
languages and many prefer to work with it for brevity’s sake.
3. Does Java Matter In Android Development?
Ans: Absolutely! Although Java will still be a core language for Android, many
libraries and tools are based on the JVM.
4. What are the best ways of learning Java for Android
development?
Ans: Look on Udemy, Codeacademy and Coursera for online courses. Head
First Java-Java: The Complete Reference are the great books.
5. How Long to Learn Java for Android Development?
Ans: It
depends, but can take 2-3 months, with regular effort.